CTLA4 and hepatocellular carcinoma: In addition, immune checkpoint inhibitor expression was significantly higher in HCC with high risk, particularly CD274, CD276, CD4, CTLA4, CXCR4, IL1A, LAG3, TGFB1, TNFRSF4, TNFRSF9 and TNFSF4 (Fig. 6B).